Dyeing process



Feb. 25, 1969 w, sT 3,429,646

DYETLNG PROCESS Filed July 15. 1965 Sheet 2 of 2 INVENTO MICHAEL WILLIAM EEC United States Patent 3,429,646 DYEING PROCESS Michael William Steed, Cranford, Hounslow, England, assignor to Lever Brothers Company, New York, N.Y., a corporation of Maine Filed July 15, 1965, Ser. No. 472,166 Claims priority, application Great Britain, Aug. 5, 1964,

31,787/ 64 US. Cl. 8-10 Int. Cl. D06p 3/10; A61k 7/12 10 Claims ABSTRACT OF THE DISCLOSURE The specification is concerned with a process for dyeing a keratinous material, such as hair, with a complex cation containing the structure:

where M is a transition metal and the missing valences have hydrogen, an organic group or an inorganic group.

where M is a transition metal; this grouping is known as the ferroin grouping where M is bivalent iron and the cuproin grouping when M is monovalent copper. Mixtures of coloured complex ions may be used.

The metal atom may be bonded to up to 6 nitrogen atoms depending upon the co-ordination number of the metal. Furthermore, the metal atom may be linked to the nitrogen atoms of three or two separate molecules or even just one molecule of the compound forming the complex with the metal, again depending on the coordination number of the metal and also on the number of coordinating groups in the particular compound forming the complex with the metal. The compound forming the complex with the metal will be referred to hereinafter as the ligand. The ligand may contain as well as the N%C=N group other groupings such as :NNC=N- or =N-N=CC=N- which chelate with transition metal ions.

Examples of structures which the ligand may form with the transition metal atom are:

The R groups (which will usually not all be the same) may be hydrogen or an organic or inorganic substituent group. Examples of such substituent groups are alkyl (for example methyl, ethyl, n-propyl, isopropyl, n-butyl) hydroxy, methoxy, amino, imino, chloro, broino, iodo, nitro, sulphonate, carboxy, cyano, phenyl, benzyl, pyridyl, methyl pyridyl, quinolyl, methyl quinolyl, and pyrryl. Further, adjacent R groups may form together with the intervening carbon or carbon and nitrogen atoms, aromatic, aliphatic or heterocyclic rings. Such rings may be substituted, for example by the above-mentioned substituent groups. p l a In structures (I) and (II) the double bonds indicated are not fixed when part of aromatic or heterocyclic aromatic rings.

The ring structures containing the metal atoms as indicated are five-membered rings and the ring in structure (I) or one of its resonant forms is always present. Typical,

' examples of these structures are (III) and (IV):

In most cases there are six donating nitrogen atoms per metal atom so that in the case of structure (III) or general structure (I) the ferrous complex is Fe(ligand) but there are examples where only four nitrogen atoms donate, e.g. the cuprous complex of structure (III) which is Cu(ligand) and some complexes may have only two donating nitrogen atoms. The above examples applied to the structure of the type (IV) would be Fe(ligancl) and Cu(ligand)X+ where X is a monodonating base, for example, ammonia, pyridine or water.

The following are examples of ligands that form com plexes containing the above chromophoric grouping with transition metals and the colours produced with bivalent iron are given. The formulae of these compounds are indicated on the accompanying formula drawing.

Formula Ligand Colour with bivalent iron I 1,10-phenanthr0line Orange 11-.-. 2,2-dipyridyl Red, III..- 2,6-bis-(apyridyl)-4-pheny1pyridine.-.- Mauve. IV 2,2"diquoinolyl (Mauve with monovalent copper). V glyoxal-bis-methylimine.. Lilac. VI biacetyl-bis-methylimine. Mauve. VII... a-pyn'dylmethylene-amino-methan Maroon-violet. VIII a-pyridylmethylene-hydrazine.. Red. IX. 1-(a-pyridylmethylene)-2-methyl Yellow-orange.

hydrazine. X 1-(a-pyridylmethylene)-2-(a-pyridyl)- Red-brown.

hydrazine. XI 1,2-bis'(a-pyridylmethylene) Red-brown hydrazine. changing to blue. XII 8-(a-pyndylmethyleneamino)- Green.

quinoline. XIII 2,4,6-tris-(a-pyzidy1)-1,3,5-triazine Blue. XIV 2,3,5,Metrakis-(a-pyridyD-pyrazine. Violet. XV 1,8-bis-(a-pyridylmethyleneamino)- Blue-violet.

methylene diamine. XVI 1,2-bis-[1-(a-pyrldylmethyieneamino)- Turquoise blue.

2-amino-benzene] ethane. XVII 1,aifis-(a-pylidylmethyleneamino)- Blue-violet.

e ane. XVIII 1-(apyridylmethyleneamirio)-2- Turquoise blue.

amino-benzene. XIX I (chpyridylmethyleneamino)-2-amino- Blue.

e ane. XX 2(a-pyridylmethyleneaminomethyl)- Red (deep blue pyridine. with cobaltous).

Not all transition metals give complexes with all the above ligands. As noted, bivalent iron, for example, does not form a complex with 2,2-diquinolyl whereas monovalent copper does. E

As examples of substituted phenanthrolines may be mentioned the 5,6-dimethyl, 4,7-diphenyl, 4,7-diphenyl- 2,9-dimethyl, S-nitro, 4-cyano, 4,7-dichloro, and S-amino derivatives.

As well as iron and copper already mentioned, other examples of transition metals that give coloured complexes with the above type of ligands are ruthenium, osmium, cobalt, nickel, moylbdenum, vanadium, chromium and rhodium. The iron (11), ruthenium (II) and osmium (II) complexes in particular with the above ligands are very stable and very intensely coloured, having on average, a molar extinction coefficient in the range 8,000l2,000. The cuprous and cobaltous complexes are similar; some of them are oxidised to the less strongly coloured cupric and cobaltic states by atmospheric oxygen. The ferric, cupric and cobaltic complexes are generally not so strongly coloured, on average being about a tenth as intense as the corresponding bivalent metal complexes.

References herein to transition metals are meant to include the metals in the Periodic Table from scandium to zinc, from yttrium to cadmium, and from lanthanum to mercury.

Many examples of the above type of metal complex are described in the literature.

Examples of keratinous materials that may be coloured by the metal complexes are hair, wool, fur, feathers, silk, skin and nails. The materials may be pretreated. For example, hair may first be treated with a shampoo or a peroxide.

It is usually most convenient to first form the complex and then apply it to the keratinous material. The complex may be formed by reacting an aqueous solution of a salt of a transition metal with a solution of a ligand. The concentration of the complex will usually be in the range 0.0001 M to 0.1 M; 0.01 M of the ferrous phenanthroline complex is equivalent to 560 ppm, iron.

Alternatively, the solution of the metal salt and the solution of the ligand may be applied to the keratinous material separately so as to form the complex in situ. To colour hair orange, for example, hair may be treated with a solution of l,l-phenanthroline followed by a solution of ferrous ions. This procedure may also be reversed.

When a solution of the coloured complex is applied to the keratinous material, the anion of the complex is usually unimportant as long as the complex salt readily dissolves and dissociates. The common anions such as chloride, sulphate, nitrate, acetate, citrate, tartrate, sulphite, and nitrite, are suitable. Anions such as iodide, perchlorate, fluoroborate. high molecular weight carboxylic acids, high molecular weight sulphonates and sulphates, may be less siutable as they tend to give less soluble salts with some complex cations.

Uptake of the coloured complex cation by the material to be dyed is dependent on the pH in the environment of the keratinous material. For the coloured complex to be taken up by the keratinous material, either the solution of the complex, or of the ligand if the metal and ligand are applied separately, must be alkaline or the keratinous material must be pretreated with an alkali; alkaline solutions of the complex or ligand may be used even when the keratinous material has been pretreated with alkali. When alkaline solutions are used their pH is desirably at least 8, and preferably from to 11. At higher pH the uptake is even better but as very alkaline solutions can produce, in the case of hair, slight damage, the pH used is generally in the range 8 to 12 and in particular at about-10 to 10.5.

Some metal complexes are very unstable above certain pHs and in using such complexes it may be necessary to pretreat the keratinous material with alkali to obtain the desired uptake of the complex; the complex then being applied to the hair from a neutral or only slightly alkaline solution (say pH less than 10) of the complex or ligand.

Examples of suitable agents for adjusting the pH of the solution of the coloured complex compound or ligand or for pretreating the keratinous material are bases such as ammonia, mono-, di-, or triethanolamine, methylamine, ethylamine, 2-amino-2-methyl-propanol, sodium hydroxide; potassium hydroxide, and alkali metal salts of weak aicds such as the sodium salts of nitrilotriacetic acid and polyphosphoric acid.

The process of the invention is satisfactorily carried out at normal room temperature, i.e, about 20 C., but increase in temperature does increase the uptake. Hair is suitably treated at a temperature of 30-35 C. as is used for conventional dyeing.

If the complex is sparingly soluble in water, watermiscible solvents and solubilizers may be used as alcohols, ketones, glycols, and nonionic and amphoteric surfaceactive agents. Typical examples are methanol, ethanol, npropanol, isopropanol, n-butanol, isobutanol, dioxane, acetone, propylene glycol, polyethylene glycols, glycerol, sorbitol, polyoxyethylene sorbitans, polyoxyethylene phenols, betaine detergents, polyoxyethylene amines and ethoxylated lanolins.

The coloured complex ions have differing fastness to hair. For example, the ferrous tris-biacetyl-bis-methylimine complex is washed off the hair with one strong shampoo, and is therefore only a temporary dyestutf, while the ferrous tris-1,l0-phenanthroline complex may still be visible after about six shampoos, although the intensity falls with each treatment.

The colours are reasonably fast to warm or cold water.

The coloured complex ions may be included in conventional dyeing preparations based on direct nitro dyes.

Concentrated solutions of strong electrolytes such as sodium chloride greatly accelerate the desorption of the complexes from the keratinous material and strong oxidising agents such as persulphate oxidise many of the complexes to the weaker coloured higher valency state.

The colourants may be applied in the presence of amphoteric and non-ionic surfactants so that a stable foam is produced giving better contact between the colourant and the keratinous material. Other ingredients commonly used in dyeing products such as, for example, foam boosters, stabilizers and thickening agents may also be included. Electrolytes such as ammonium sulphate may be included as buffering agents so that the pH can be adjusted with accuracy.

The desorption of the complexes from the keratinous material is greatly accelerated by strong electrolytes such as sodium chloride, as noted above, and warm concentrated solutions of these are suitable for removing the colours from, for example, hair and skin. A solution of potassium iodide in water or a water/alcohol mixture can also be used.

The following examples illustrate the invention.

EXAMPLE 1 0.12 g. of 1,10-phenanthroline monohydrate was added to a solution of 0.078 g. of ferrous ammonium sulphate hexahydrate in 50 ml. of water. When all of the phenanthroline was dissolved the solution was diluted to ml. to give a 0.002 M solution of ferrous tris-l,l0 phenanthroline sulphate.

The pH of 5 ml. of this solution was adjusted to 10.5 with ammonia, and a small switch (0.1 g.) of natural Scandinavian blonde hair was immersed in it for 5 minutes. The switch was then thoroughly rinsed in warm water leaving the hair a bright orange colour.

EXAMPLE 2 0.02 M solutions of ferrous tris-1,10-phenanthroline chloride, ferrous bis-2,3,5,6-tetrakis-(a-pyridyl)-pyrazine chloride and ferrous bis-8-(a-pyridylmethyleneamine)-6- methoxyquinoline chloride were prepared and mixed in equal proportions. The pH of 5 ml. of this mixture was adjusted to 10.5 with monoethanolamine and a sw tch of grey hair was immersed in this solution for minutes. The switch was then rinsed in warm water leaving the hair a dark brown colour.

EXAMPLE 3 A small switch of natural Scandinavian blonde hair was immersed in a small quantity of a 1% solution of sodium carbonate for 5 minutes. The switch was removed, rinsed with water and immersed in 5 ml. of a neutral 0.002 M solution of the tris-(a-pyridylmethyleneamino-methane)- ferrous complex cation for 10 minutes. The switch was removed and rinsed with water. The hair was coloured a purple shade.

EXAMPLE 4 A small switch of natural Scandinavian blonde hair was immersed in a 0.01 M solution of ferrous ammonium sulphate for 5 minutes. The switch was removed, rinsed with Water and immersed for 5 minutes in 5 ml. of a 0.03 M solution of 1,10-phenanthroline adjusted to pH 10.5 with ammonia. The switch was removed and washed with water. The hair was coloured a bright orange shade.

EXAMPLE 5 A thickened 0.1% solution of the bis-l-(a-pyridylmethylene)-2-(u-pyridyl)-hydrazine cobaltous complex cation adjusted to pH 10 with sodium hydroxide was applied to a head of hair of a natural light brown colour for 10 minutes. The hair was then shampooed and rinsed. The hair had changed colour to a deeper red-brown shade.

EXAMPLE 6 A small switch of Scandinavian blonde hair was immersed for 5 minutes in an aqueous solution of the cuprous bis-4,7-diphenyl-2,9-dimethyl 1,10 phenanthroline cation, containing 100 ppm. of the complex cation, and adjusted to pH 11. The switch was removed and rinsed with water. The hair was coloured an orange-brown shade.

EXAMPLE 7 An 0.02% aqueous solution of pH 11 of the ferrous bis-2,3,5,6-tetrakis-(a-pyridyD-pyrazine complex cation was applied to a head of bleached blonde hair. The hair was then shampooed and rinsed. The effect of the applied metal complex was to cancel the yellowish tint of the bleached hair leaving it a more natural blonde shade. (From a more concentrated solution, this complex colours blonde hair a violet shade.)

EXAMPLE 8 An aqueous solution of the ruthenous complex cation of 2,2'-dipyridyl was used to colour a switch of blonde Scandinavian hair by immersion of the switch in the solution for 5 minutes. The solution had a pH of 10.5 and contained 100 p.p.m. of the complex cation. The switch was removed and rinsed with water. The hair was coloured a golden-yellow shade.

EXAMPLE 9 A small switch of natural Scandinavian hair was immersed in a 0.1% solution of the 2-(a-pyridyl-methyleneaminomethyl)-pyridine nickel complex cation for 10 minutes. The pH of the solution was adjusted to 9 with sodium hydroxide solution. The switch was removed and rinsed with water. The hair was coloured a red-pink shade.

EXAMPLE 10 A small switch of natural Scandinavian hair was immersed in a 0.1% solution of the 1,8-bis-(a-pyridy1methyleneamino)-triethylene diamine ferrous complex cation for 10 minutes. The pH of the solution was adjusted to 11 with sodium hydroxide solution. The switch was removed and rinsed with water. The hair was coloured a blue-violet shade.

EXAMPLE 11 Example 10 was repeated except that the complex cation used was the ferrous complex of l,2-bis-[ l'-(a-pyridylmethyleneamino)-2-amino-benzene]-ethane. The hair was coloured a turquoise-blue shade.

EXAMPLE 12 Example 10 was repeated except that the complex cation used was the ferrous complex of l,2-bis-(a-pyridylmethyleneamino)-ethane. The hair was coloured a blue-violet shade.

EXAMPLE 13 Example 10 was repeated except that the complex cation used was the bis-l-(a-pyridylrnethyleneamino) -2- amino-benzene ferrous complex. The hair was coloured a turquoise-blue shade.

EXAMPLE 14 Example 10 was repeated except that the complex cation used was the ferrous bis-l-(a-pyridylmethyleneamino)-2-amino-ethane complex. The hair was coloured a blue shade.

EXAMPLE 15 Example 10 was repeated except that the complex cation used was the ferrous tris-l-(a-pyridylmethylene)-2- methyl-hydrazine complex and in this instance the pH was only 9.5. The hair was coloured a yellow-orange shade.

It will be understood from the foregoing that the colouring agents used in the process of this invention are cationic metal complex ions involving a specific chromophore. The charge of the complex is due to the metal ion and the colourants are therefore distinguished from azodye metal complex acid dyes where the metal atom contributes only a subsidiary part of the chromophore. In these acid dyes the charge on the metal is neutralised and the final negative nature of the dye is due to sulphonic acid groups.

What I claim is:

1. A process for dyeing a keratinous material in which the keratinous material is coloured by means of a complex cation containing the chromophoric grouping consisting of a five-membered ring containing a transition metal atom, two carbon atoms adjacent to one another, two nitrogen atoms and conjugated double bonds, the two nitrogen atoms being bonded to the metal atom and having the structure:

where M is a transition metal and the missing valences have hydrogen, an organic group or an inorganic group.

2. A process for dyeing a keratinous material in which the keratinous material is coloured by means of a complex cation containing the chromophoric ferroin grouping.

3. A process for dyeing a keratinous material in which the keratinous material is coloured by means of a complex cation containing the chromophoric cuproin groupmg.

4. A process as claimed in claim 1 wherein the transition metal is bivalent cobalt.

5. A process as claimed in claim 1 wherein the keratinous material is coloured by treatment with an aqueous alkaline solution of the coloured complex cation.

6. A process as claimed in claim 1 wherein the keratinous material is pretreated with an alkali and then treated with a neutral solution of the coloured complex cation.

7 8 7. A process as claimed in claim 1 wherein the kerati- References Cited nous material is pretreated with an alkali and then treated UNITED STATES PATENTS with an alkaline solution of the coloured complex cation. 8. A process as claimed in claim 5 wherein the alkaline solution has a pH of from about 8 to about 12.

9. A process as claimed in claim 7 wherein the alkaline TRAVIS BROWN, Primary Examiner. solution of the coloured complex cation has a pH of less 1 E. CALLAGHAN, Assistant Examiner. than about 10. Y

10. A process as claimed in claim 1 wherein the kerati- CL nous material is human hair. 10 3 54 

